In the manufacturing industry, like the chemical, pharmaceutical, coating, recycling and oil industry, exists a broad variety of sources for emissions which are released in the environment, which is not desirable. For example, in chemical reactions, emissions of reaction components, additives and solvents may be released. During distillation, vapors of chemicals or solvents may be released. During coating of cars, vapors of coatings, additives and solvents may be released. During recycling of polymers, monomers or oligomers of the hydrolyzed polymer may be released. During cleaning of reactors, chemicals and solvents may be released.
Before, during and after the polymerization reaction for the manufacture of thermoplastic polymers like polyamides, polyester, polyolefins, polycarbonates, polystyrenes, polyacrylonitriles, polyurethanes, polysulfones, polyethersulfones, polyvinylchloride, copolymers and mixtures thereof, monomer vapors may be released in the environment from transportation tanks, storage tanks, pipelines, ducts, polymerization reactors, polymer melts, polymer strands water bath, cutters, dryers and the like, which is not desirable. During thermoplastic polymer processing like injection molding or extrusion the thermoplastic polymers are for example extruded through an extruder into strands for chip production or into films, fibers, profiles, tubes and the like. During the extrusion at a temperature of from about 180.degree. to about 350.degree. C., monomer or oligomer vapors, compounds formed by thermal evaporation, thermal decomposition, or vapors of additives are released from the surface of the extruded polymers, which are leaving the nozzle of the extruder. These vapors evaporate immediately into an aerosol that would form deposits in the neighborhood of the extruder and therefore must be removed, which is usually done by the quench air removal. The exhaust air is usually released into the environment, which is not desirable.
A filament quenching apparatus is known from U.S. Pat. No. 3,619,452 which comprises a quenching chamber and a gas entry chamber. The quench air exits the quenching apparatus without further treatment.
U.S. Pat. No. 4,676,807 discloses a process for removal of liquid aerosols from gaseous streams by passing the stream through a coalescing filter. In the examples oil and water aerosols were tested.
U.S. Pat. No. 4,759,782 which is a C.I.P. of an application which issued as U.S. Pat. No. 4,676,807 described above, discloses the coalescing filter for removal of liquid aerosols from gaseous streams.
U.S. Pat. No. 5,219,585 discloses a monomer exhaust system for exhausting fumes released from a melt spinning process which has a housing, a nozzle for the collection of the fumes, a duct, a drawing force for moving the fumes and rinsing means for automatically purging said exhaust system of condensed fume deposits.
An object of the present invention was to provide a process for removing emissions from a broad variety of emission sources.
Another object of the present invention was to provide a process for removing of emissions from polymerization operations and thermoplastic polymer processing operations.
Another object was to remove emissions from fiber spinning operations.
Another object was to remove emissions from polycaprolactam fiber spinning operations.